Jen collects blood samples to help her identify the hatchlings' fathers.
Photo courtesy of Earthwatch Institute

Identifying the Hatchlings' Fathers
by Jennifer Crim, expedition team member

Hi. I'm Jen. I am working on my Master's Degree in Environmental Science and have been at Playa Grande since September. I have always loved turtles and have been especially excited to work on this project because they are endangered. I plan on working to help save endangered species of all kinds once I finish school.

Although the main focus of our work at Playa Grande is to increase the number of turtles in the ocean, I have a project of my own. I am conducting a "paternity" study. That means that I am trying to identify who the hatchlings' fathers
are.

Male leatherback turtles are very hard to study because they always stay out in the open waters. Females are easier to study because they come up on the beaches to nest.

For my study I collect very small blood samples from the female turtles and their babies. So far I have taken 32 blood samples of the adult females and have only three more to do. No hatchlings have emerged from their eggs, so I do not have any blood samples from them yet.

Taking blood from the turtles is very easy and it does not hurt. I am using a new method to collect blood from the adults that simply involves pricking the skin of their wrist with a finger pricker. Then I use a syringe to collect the blood off the skin. It takes only two minutes.

Some species of sea turtles, like loggerheads, lay multipaternal nests. A multipaternal nest occurs when the hatchlings coming from the same nest have the same mom but different dads. Normally the nests have two or three different fathers.

My paternity analysis will tell us if this specific population of has one or many fathers per nest. Also my study will give us an idea of how many sexually mature males there are in the population at Playa Grande. By looking at the DNA of the fathers from all of the nests I can tell if there are many different males fathering nests or if just a few males are fathering the nests of all the female turtles.

If just a few males exist that may be one of the reasons the population is decreasing so fast. Hopefully my study will tell me if this is the problem so that we can help the turtles before it is too late.

The first clutch of eggs is expected to hatch next week. I cannot wait to see the hatchlings. They look exactly like their moms, but they are much smaller, of course!